The present disclosure relates generally to an energy storage system configured to store and discharge energy to satisfy the energy load of a building or campus. The present disclosure relates more particularly to an energy system which optimally allocates energy storage assets (e.g., batteries, thermal energy storage) while accounting for multiple demand charges.
Demand charges are costs imposed by utilities based on the peak consumption of a resource purchased from the utilities during various demand charge periods (i.e., the peak amount of the resource purchased from the utility during any time step of the applicable demand charge period). For example, an electric utility may define one or more demand charge periods and may impose a separate demand charge based on the peak electric consumption during each demand charge period. Electric energy storage can help reduce peak consumption by storing electricity in a battery when energy consumption is low and discharging the stored electricity from the battery when energy consumption is high, thereby reducing peak electricity purchased from the utility during any time step of the demand charge period. It can be difficult and challenging to optimally allocate energy storage assets in the presence of multiple demand charges.